Oh I know this happens more than I care to think about, but to me, I don't see any reason whatsoever to do something so cruel as this. There are plenty of shelters, S.P.C.A.'s, we even have an organization that will come and pick up if you don't have a car. It only cost $20.00. There is just no need for this to happen.
Hats off to you Twisterdog for stopping and checking out any boxes. It must have been so hard on you when you found any that were dead. I would have been a basket case.